From: Catalin Marinas <catalin.marinas@arm.com>
To: linux-arm-kernel@lists.infradead.org
Cc: Will Deacon <will@kernel.org>,
Vincenzo Frascino <vincenzo.frascino@arm.com>,
Szabolcs Nagy <szabolcs.nagy@arm.com>,
Richard Earnshaw <Richard.Earnshaw@arm.com>,
Kevin Brodsky <kevin.brodsky@arm.com>,
Andrey Konovalov <andreyknvl@google.com>,
Peter Collingbourne <pcc@google.com>,
linux-mm@kvack.org, linux-arch@vger.kernel.org
Subject: [PATCH v2 13/19] mm: Introduce arch_validate_flags()
Date: Wed, 26 Feb 2020 18:05:20 +0000 [thread overview]
Message-ID: <20200226180526.3272848-14-catalin.marinas@arm.com> (raw)
In-Reply-To: <20200226180526.3272848-1-catalin.marinas@arm.com>
Similarly to arch_validate_prot() called from do_mprotect_pkey(), an
architecture may need to sanity-check the new vm_flags.
Define a dummy function always returning true. In addition to
do_mprotect_pkey(), also invoke it from mmap_region() prior to updating
vma->vm_page_prot to allow the architecture code to veto potentially
inconsistent vm_flags.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
---
Notes:
v2:
- Some comments updated.
include/linux/mman.h | 13 +++++++++++++
mm/mmap.c | 9 +++++++++
mm/mprotect.c | 6 ++++++
3 files changed, 28 insertions(+)
diff --git a/include/linux/mman.h b/include/linux/mman.h
index 15c1162b9d65..09dd414b81b6 100644
--- a/include/linux/mman.h
+++ b/include/linux/mman.h
@@ -103,6 +103,19 @@ static inline bool arch_validate_prot(unsigned long prot, unsigned long addr)
#define arch_validate_prot arch_validate_prot
#endif
+#ifndef arch_validate_flags
+/*
+ * This is called from mmap() and mprotect() with the updated vma->vm_flags.
+ *
+ * Returns true if the VM_* flags are valid.
+ */
+static inline bool arch_validate_flags(unsigned long flags)
+{
+ return true;
+}
+#define arch_validate_flags arch_validate_flags
+#endif
+
/*
* Optimisation macro. It is equivalent to:
* (x & bit1) ? bit2 : 0
diff --git a/mm/mmap.c b/mm/mmap.c
index 6756b8bb0033..e52e433849c3 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -1794,6 +1794,15 @@ unsigned long mmap_region(struct file *file, unsigned long addr,
vma_set_anonymous(vma);
}
+ /* Allow architectures to sanity-check the vm_flags */
+ if (!arch_validate_flags(vma->vm_flags)) {
+ error = -EINVAL;
+ if (file)
+ goto unmap_and_free_vma;
+ else
+ goto free_vma;
+ }
+
vma_link(mm, vma, prev, rb_link, rb_parent);
/* Once vma denies write, undo our temporary denial count */
if (file) {
diff --git a/mm/mprotect.c b/mm/mprotect.c
index 7a8e84f86831..1c760058ace3 100644
--- a/mm/mprotect.c
+++ b/mm/mprotect.c
@@ -543,6 +543,12 @@ static int do_mprotect_pkey(unsigned long start, size_t len,
goto out;
}
+ /* Allow architectures to sanity-check the new flags */
+ if (!arch_validate_flags(newflags)) {
+ error = -EINVAL;
+ goto out;
+ }
+
error = security_file_mprotect(vma, reqprot, prot);
if (error)
goto out;
next prev parent reply other threads:[~2020-02-26 18:06 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-26 18:05 [PATCH v2 00/19] arm64: Memory Tagging Extension user-space support Catalin Marinas
2020-02-26 18:05 ` [PATCH v2 01/19] arm64: alternative: Allow alternative_insn to always issue the first instruction Catalin Marinas
2020-02-26 18:05 ` [PATCH v2 02/19] arm64: mte: system register definitions Catalin Marinas
2020-02-26 18:05 ` [PATCH v2 03/19] arm64: mte: CPU feature detection and initial sysreg configuration Catalin Marinas
2020-02-26 18:05 ` [PATCH v2 04/19] arm64: mte: Use Normal Tagged attributes for the linear map Catalin Marinas
2020-03-05 16:21 ` Steven Price
2020-03-05 16:38 ` Catalin Marinas
2020-02-26 18:05 ` [PATCH v2 05/19] arm64: mte: Assembler macros and default architecture for .S files Catalin Marinas
2020-02-26 18:05 ` [PATCH v2 06/19] arm64: mte: Tags-aware clear_page() implementation Catalin Marinas
2020-02-26 18:05 ` [PATCH v2 07/19] arm64: mte: Tags-aware copy_page() implementation Catalin Marinas
2020-02-26 18:05 ` [PATCH v2 08/19] arm64: Tags-aware memcmp_pages() implementation Catalin Marinas
2020-02-26 18:05 ` [PATCH v2 09/19] arm64: mte: Add specific SIGSEGV codes Catalin Marinas
2020-02-26 19:05 ` Eric W. Biederman
2020-02-26 19:26 ` Catalin Marinas
2020-02-26 22:33 ` kbuild test robot
2020-02-27 11:05 ` Catalin Marinas
2020-02-27 15:20 ` Eric W. Biederman
2020-02-26 18:05 ` [PATCH v2 10/19] arm64: mte: Handle synchronous and asynchronous tag check faults Catalin Marinas
2020-02-27 11:50 ` Catalin Marinas
2020-02-26 18:05 ` [PATCH v2 11/19] mm: Introduce arch_calc_vm_flag_bits() Catalin Marinas
2020-02-26 18:05 ` [PATCH v2 12/19] arm64: mte: Add PROT_MTE support to mmap() and mprotect() Catalin Marinas
2020-02-26 18:05 ` Catalin Marinas [this message]
2020-02-26 18:05 ` [PATCH v2 14/19] arm64: mte: Validate the PROT_MTE request via arch_validate_flags() Catalin Marinas
2020-02-26 18:05 ` [PATCH v2 15/19] mm: Allow arm64 mmap(PROT_MTE) on RAM-based files Catalin Marinas
2020-02-26 18:05 ` [PATCH v2 16/19] arm64: mte: Allow user control of the tag check mode via prctl() Catalin Marinas
2020-03-09 13:53 ` Kevin Brodsky
2020-02-26 18:05 ` [PATCH v2 17/19] arm64: mte: Allow user control of the generated random tags " Catalin Marinas
2020-02-26 18:05 ` [PATCH v2 18/19] arm64: mte: Kconfig entry Catalin Marinas
2020-02-26 18:05 ` [PATCH v2 19/19] arm64: mte: Add Memory Tagging Extension documentation Catalin Marinas
2020-03-09 14:30 ` Kevin Brodsky
2020-03-11 22:17 ` Richard Henderson
2020-03-12 9:50 ` Catalin Marinas
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